The present invention relates generally to methods of treating commercial grade preservatives having offensive odors and/or tastes to remove the off-odors and off-tastes from the preservatives. In particular, the invention relates to methods for removing undesirable tastes and odors from commercial grade preservatives by dissolving the preservative in a solvent and passing the solution through a filter to remove the organic acid impurities.
The growth of mold, rope, yeasts and bacteria is a significant problem in packaged or processed foods, cosmetics, personal care products, and pharmaceuticals. The growth of mold, rope, yeasts and bacteria not only significantly reduces the useful shelf life of such products, thus increasing the sellers"" direct costs due to stale or moldy products that cannot be sold, but also requires that certain items be refrigerated during shipping and/or at the marketplace, which causes additional indirect expenses for the end seller of the product.
Various preservatives on the market, including commercial grade alkyl parabens and sodium benzoate, are limited in their usefulness because they tend to impart undesirable off-flavors and/or odors to the final product. As a result, the most effective preservatives for a particular product often cannot be used because they would impart undesirable flavors and/or odors. In other cases, the preservative cannot be used at its most effective concentration and must be diluted to minimize the off-flavors and off-odors.
Thus, a need exists for a method of treating commercial grade preservative products to remove the offensive odors and flavors without altering the primary composition and effectiveness of the preservatives.
The present invention provides novel processes for removing undesirable odors and flavors from commercial grade preservatives. The processes include the steps of: selecting a commercial grade preservative that contains a small amount of organic acid impurities; preparing a solution of the preservative using a solvent in which the preservative is soluble; and passing the preservative solution through a filter that removes the organic acid impurities from the solution.
According to a first embodiment, the filter is a bed of anion exchange resin that separates the organic acid impurities from the solution. According to a second embodiment, the filter contains a metal cation that converts the organic acid impurities into insoluble salts which are then removed from the solution. The solvent used in the process is selected based on what the particular preservative is soluble in. For example, water or methanol or mixtures thereof can be used for the solvent. The undesirable tastes and odors, principally caused by organic acids, are retained in the filter, while the preservative solution passes through the filter. The solvent can be removed from the preservative solution, e.g., by evaporation, after the solution is passed through the filter.